<template>
  <div id="tags-view-container" class="tags-view-container">
    <ScrollPane ref="scrollPane" class="tags-view-wrapper" @scroll="handleScroll">
      <router-link v-for="tag in visitedViews" ref="tag" :key="tag.path" :class="isActive(tag) ? 'active' : ''"
        :to="{ path: tag.path, query: tag.query, fullPath: tag.fullPath }" tag="span" class="tags-view-item"
        @click.middle.native="!isAffix(tag) ? closeSelectedTag(tag) : ''"
        @contextmenu.prevent.native="openMenu(tag, $event)">
        {{ generateTitle(tag.title) }}
        <span v-if="!isAffix(tag)" class="el-icon-close" @click.prevent.stop="closeSelectedTag(tag)"></span>
      </router-link>
    </ScrollPane>
    <ul v-show="visible" :style="{ left: left + 'px', top: top + 'px' }" class="contextmenu">
      <li @click="refreshSelectedTag(selectedTag)">
        {{ $t("tagsView.refresh") }}
      </li>
      <li v-if="!isAffix(selectedTag)" @click="closeSelectedTag(selectedTag)">
        {{ $t("tagsView.close") }}
      </li>
      <li @click="closeOthersTags">{{ $t("tagsView.closeOthers") }}</li>
      <li @click="closeAllTags(selectedTag)">{{ $t("tagsView.closeAll") }}</li>
    </ul>
  </div>
</template>

<script>
import ScrollPane from "./ScrollPane";
import { generateTitle } from "@/utils/i18n";
import path from "path";

export default {
  components: { ScrollPane },
  data () {
    return {
      visible: false,
      top: 0,
      left: 0,
      selectedTag: {},
      affixTags: []
    };
  },
  computed: {
    visitedViews () {
      return this.$store.state.tagsView.visitedViews;
    },
    routes () {
      return this.$store.state.permission.routes;
    }
  },
  watch: {
    $route () {
      this.addTags();
      this.moveToCurrentTag();
    },
    visible (value) {
      if (value)
      {
        document.body.addEventListener("click", this.closeMenu);
      } else
      {
        document.body.removeEventListener("click", this.closeMenu);
      }
    }
  },
  mounted () {
    this.initTags();
    this.addTags();
  },
  methods: {
    generateTitle, // generateTitle by vue-i18n
    isActive (route) {
      return route.path === this.$route.path;
    },
    isAffix (tag) {
      return tag.meta && tag.meta.affix;
    },
    filterAffixTags (routes, basePath = "/") {
      let tags = [];
      routes.forEach(route => {
        if (route.meta && route.meta.affix)
        {
          const tagPath = path.resolve(basePath, route.path);
          tags.push({
            fullPath: tagPath,
            path: tagPath,
            name: route.name,
            meta: { ...route.meta }
          });
        }
        if (route.children)
        {
          const tempTags = this.filterAffixTags(route.children, route.path);
          if (tempTags.length >= 1)
          {
            tags = [...tags, ...tempTags];
          }
        }
      });
      return tags;
    },
    initTags () {
      const affixTags = (this.affixTags = this.filterAffixTags(this.routes));
      for (const tag of affixTags)
      {
        // Must have tag name
        if (tag.name)
        {
          this.$store.dispatch("tagsView/addVisitedView", tag);
        }
      }
    },
    addTags () {
      const { name } = this.$route;
      if (name)
      {
        this.$store.dispatch("tagsView/addView", this.$route);
      }
      return false;
    },
    moveToCurrentTag () {
      const tags = this.$refs.tag;
      this.$nextTick(() => {
        for (const tag of tags)
        {
          if (tag.to.path === this.$route.path)
          {
            this.$refs.scrollPane.moveToTarget(tag);
            // when query is different then update
            if (tag.to.fullPath !== this.$route.fullPath)
            {
              this.$store.dispatch("tagsView/updateVisitedView", this.$route);
            }
            break;
          }
        }
      });
    },
    refreshSelectedTag (view) {
      this.$store.dispatch("tagsView/delCachedView", view).then(() => {
        const { fullPath } = view;
        this.$nextTick(() => {
          this.$router.replace({
            path: "/redirect",
            query: {
              fullPath
            }
          });
        });
      });
    },
    closeSelectedTag (view) {
      this.$store
        .dispatch("tagsView/delView", view)
        .then(({ visitedViews }) => {
          if (this.isActive(view))
          {
            this.toLastView(visitedViews, view);
          }
        });
    },
    closeOthersTags () {
      this.$router.push(this.selectedTag);
      this.$store
        .dispatch("tagsView/delOthersViews", this.selectedTag)
        .then(() => {
          this.moveToCurrentTag();
        });
    },
    closeAllTags (view) {
      this.$store.dispatch("tagsView/delAllViews").then(({ visitedViews }) => {
        if (this.affixTags.some(tag => tag.path === view.path))
        {
          return;
        }
        this.toLastView(visitedViews, view);
      });
    },
    toLastView (visitedViews, view) {
      const latestView = visitedViews.slice(-1)[0];
      if (latestView)
      {
        this.$router.push(latestView.fullPath);
      } else
      {
        // now the default is to redirect to the home page if there is no tags-view,
        // you can adjust it according to your needs.
        if (view.name === "Dashboard")
        {
          // to reload home page
          this.$router.replace({ path: "/redirect" + view.fullPath });
        } else
        {
          this.$router.push("/");
        }
      }
    },
    openMenu (tag, e) {
      const menuMinWidth = 105;
      const offsetLeft = this.$el.getBoundingClientRect().left; // container margin left
      const offsetWidth = this.$el.offsetWidth; // container width
      const maxLeft = offsetWidth - menuMinWidth; // left boundary
      const left = e.clientX - offsetLeft + 15; // 15: margin right

      if (left > maxLeft)
      {
        this.left = maxLeft;
      } else
      {
        this.left = left;
      }

      this.top = e.clientY - 40;
      this.visible = true;
      this.selectedTag = tag;
    },
    closeMenu () {
      this.visible = false;
    },
    handleScroll () {
      this.closeMenu();
    }
  }
};
</script>

<style lang="scss" scoped>
@import "~@/styles/variables.scss";

.tags-view-container {
  height: $tagsViewHeight;
  width: 100%;

  .tags-view-wrapper {
    .el-scrollbar__view {
      .tags-view-item {
        display: inline-block;
        position: relative;
        cursor: pointer;
        height: $tagsViewHeight;
        line-height: $tagsViewHeight;
        color: #6B8DB6;
        background-color: $tagsViewBgColor;
        padding: 0 8px;
        font-size: 14px;
        border: 1px solid #ccc;

        &.active {
          background-color: $tagsViewActiveBgColor;
          color: #3C90FE;
          border-color: $tagsViewActiveBgColor;
        }
      }
    }
  }

  .contextmenu {
    margin: 0;
    background: #fff;
    z-index: 3000;
    position: absolute;
    list-style-type: none;
    padding: 5px 0;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 400;
    color: #333;
    box-shadow: 2px 2px 3px 0 rgba(0, 0, 0, 0.3);

    li {
      margin: 0;
      padding: 7px 16px;
      cursor: pointer;

      &:hover {
        background: #eee;
      }
    }
  }
}
</style>

<style lang="scss">
//reset element css of el-icon-close
.tags-view-wrapper {
  .tags-view-item {
    .el-icon-close {
      width: 16px;
      height: 16px;
      vertical-align: 2px;
      border-radius: 50%;
      text-align: center;
      transition: all 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
      transform-origin: 100% 50%;

      &:before {
        transform: scale(0.6);
        display: inline-block;
        vertical-align: -3px;
      }

      &:hover {
        background-color: #b4bccc;
        color: #fff;
      }
    }
  }
}
</style>
